N.Y.C. Admin. Code § 24-301: § 24-301 Assessment of city property used for water purposes.

a. The lands taken, or to be taken, for storage, reservoirs, or for other constructions necessary for the introduction and maintenance of a sufficient supply of water in the city, or for the purpose of preventing contamination or pollution, shall be assessed and taxed in the counties in which they are or may be located, in the manner prescribed by law, exclusive of the aqueducts.

b. This section shall not be construed to prevent the assessors in the county of Nassau from assessing for taxation the pumping stations and buildings located in such county.